1. Field
The present disclosure relates to wireless communication systems, and in particular, to adaptive transmission during almost blank subframes (ABSs) in a wireless communication system.
2. Description of the Related Technology
Recently, there has been a significant progress in wireless technologies, especially in mobile telecommunication technologies. The Second Generation technology, also known as “Global System for Mobile Communications (GSM)” and the Third Generation (3G) technology have been commercially deployed successfully to provide voice, text, and data services for mobile communication devices.
Advanced mobile communication technologies have been developed to provide better mobile communication services than the previous technologies. Among them is the Long Term Evolution of Universal Mobile Telecommunications System (UMTS), which is known as “LTE.” The LTE system has been developed as part of the 3rd Generation Partnership Project (3GPP), which is one of standards development groups for mobile radio systems. Details of the LTE system have been published or proposed in 3GPP LTE Releases 8 to 11. 3GPP LTE Releases 8 to 11 and beyond can be collectively referred to as “LTE” in the context of this document. 3GPP Releases 10, 11 and later releases are collectively referred to as “LTE Advanced” (LTE-A), and propose more advanced features than 3GPP Release 9 or earlier. As used herein, the term “legacy” or “legacy device” can refer to signals, user equipments, network components, and/or other entities that comply with 3GPP Release 9 or earlier release, but do not comply with LTE Advanced.
In LTE Advanced, various new features have been introduced. Among them is a heterogeneous network that includes different types of network access nodes or devices to provide a better coverage for mobile devices than a homogeneous network (which includes the same type of access nodes). However, due to the co-existence of different types of network access nodes within a single wireless network, interference problems between various mobile devices and access nodes have been identified, and various schemes have been proposed to resolve such problems. One of such schemes is the use of Almost Blank Subframes (ABSs), which will be described later in detail. However, the use of ABS reduces the throughput of a wireless communication system, and thus there is a need for a scheme that can increase the throughput while reducing interference in the context of ABS.